Email applications have expanded beyond transmitting and rendering text-only messages and now often incorporate many formatting and graphics capabilities through use of hypertext markup language (HTML) and in some cases rich text format (RTF). Users can now prepare messages in a manner reminiscent of word processing applications. However, styles and other formatting applied by the sender (either intentionally or as a default by the sender's email application) may not be appreciated by the recipient. For example, very small font sizes or certain glyph variations may be difficult for the recipient to read. In addition, as electronic messages traverse different clients and services, a single series of messages containing multiple replies and forwards may contain a mix of font faces, sizes and colors resulting from different default—or sender-intentional—formatting choices in the various messaging client applications. The result may be that electronic messages look cluttered and confusing to recipients.
Some existing techniques to address recipient-based preferences have focused on normalizing the content of the electronic messages by enforcing stylistic changes on all the text in the message. However, these existing techniques may alter formatting intentionally introduced by the sender of the electronic message, causing text to lose its intended emphasis.